/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * --------------
 * AxisSpace.java
 * --------------
 * (C) Copyright 2003-2008, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 03-Jul-2003 : Version 1 (DG);
 * 14-Aug-2003 : Implemented Cloneable (DG);
 * 18-Aug-2003 : Implemented Serializable (DG);
 * 17-Mar-2004 : Added a toString() method for debugging (DG);
 * 07-Jan-2005 : Updated equals() method (DG);
 * 11-Jan-2005 : Removed deprecated methods in preparation for 1.0.0
 *               release (DG);
 *
 */

package net.droidsolutions.droidcharts.core.axis;

import java.io.Serializable;

import net.droidsolutions.droidcharts.awt.Rectangle2D;
import net.droidsolutions.droidcharts.common.RectangleEdge;

/**
 * A record that contains the space required at each edge of a plot.
 */
public class AxisSpace implements Cloneable, Serializable {

	/** For serialization. */
	private static final long serialVersionUID = -2490732595134766305L;

	/** The top space. */
	private double top;

	/** The bottom space. */
	private double bottom;

	/** The left space. */
	private double left;

	/** The right space. */
	private double right;

	/**
	 * Creates a new axis space record.
	 */
	public AxisSpace() {
		this.top = 0.0;
		this.bottom = 0.0;
		this.left = 0.0;
		this.right = 0.0;
	}

	/**
	 * Returns the space reserved for axes at the top of the plot area.
	 * 
	 * @return The space (in Java2D units).
	 */
	public double getTop() {
		return this.top;
	}

	/**
	 * Sets the space reserved for axes at the top of the plot area.
	 * 
	 * @param space
	 *            the space (in Java2D units).
	 */
	public void setTop(double space) {
		this.top = space;
	}

	/**
	 * Returns the space reserved for axes at the bottom of the plot area.
	 * 
	 * @return The space (in Java2D units).
	 */
	public double getBottom() {
		return this.bottom;
	}

	/**
	 * Sets the space reserved for axes at the bottom of the plot area.
	 * 
	 * @param space
	 *            the space (in Java2D units).
	 */
	public void setBottom(double space) {
		this.bottom = space;
	}

	/**
	 * Returns the space reserved for axes at the left of the plot area.
	 * 
	 * @return The space (in Java2D units).
	 */
	public double getLeft() {
		return this.left;
	}

	/**
	 * Sets the space reserved for axes at the left of the plot area.
	 * 
	 * @param space
	 *            the space (in Java2D units).
	 */
	public void setLeft(double space) {
		this.left = space;
	}

	/**
	 * Returns the space reserved for axes at the right of the plot area.
	 * 
	 * @return The space (in Java2D units).
	 */
	public double getRight() {
		return this.right;
	}

	/**
	 * Sets the space reserved for axes at the right of the plot area.
	 * 
	 * @param space
	 *            the space (in Java2D units).
	 */
	public void setRight(double space) {
		this.right = space;
	}

	/**
	 * Adds space to the top, bottom, left or right edge of the plot area.
	 * 
	 * @param space
	 *            the space (in Java2D units).
	 * @param edge
	 *            the edge (<code>null</code> not permitted).
	 */
	public void add(double space, RectangleEdge edge) {
		if (edge == null) {
			throw new IllegalArgumentException("Null 'edge' argument.");
		}
		if (edge == RectangleEdge.TOP) {
			this.top += space;
		} else if (edge == RectangleEdge.BOTTOM) {
			this.bottom += space;
		} else if (edge == RectangleEdge.LEFT) {
			this.left += space;
		} else if (edge == RectangleEdge.RIGHT) {
			this.right += space;
		} else {
			throw new IllegalStateException("Unrecognised 'edge' argument.");
		}
	}

	/**
	 * Ensures that this object reserves at least as much space as another.
	 * 
	 * @param space
	 *            the other space.
	 */
	public void ensureAtLeast(AxisSpace space) {
		this.top = Math.max(this.top, space.top);
		this.bottom = Math.max(this.bottom, space.bottom);
		this.left = Math.max(this.left, space.left);
		this.right = Math.max(this.right, space.right);
	}

	/**
	 * Ensures there is a minimum amount of space at the edge corresponding to
	 * the specified axis location.
	 * 
	 * @param space
	 *            the space.
	 * @param edge
	 *            the location.
	 */
	public void ensureAtLeast(double space, RectangleEdge edge) {
		if (edge == RectangleEdge.TOP) {
			if (this.top < space) {
				this.top = space;
			}
		} else if (edge == RectangleEdge.BOTTOM) {
			if (this.bottom < space) {
				this.bottom = space;
			}
		} else if (edge == RectangleEdge.LEFT) {
			if (this.left < space) {
				this.left = space;
			}
		} else if (edge == RectangleEdge.RIGHT) {
			if (this.right < space) {
				this.right = space;
			}
		} else {
			throw new IllegalStateException(
					"AxisSpace.ensureAtLeast(): unrecognised AxisLocation.");
		}
	}

	/**
	 * Shrinks an area by the space attributes.
	 * 
	 * @param area
	 *            the area to shrink.
	 * @param result
	 *            an optional carrier for the result.
	 * 
	 * @return The result.
	 */
	public Rectangle2D shrink(Rectangle2D area, Rectangle2D result) {
		if (result == null) {
			result = new Rectangle2D.Double();
		}
		result.setRect(area.getX() + this.left, area.getY() + this.top, area
				.getWidth()
				- this.left - this.right, area.getHeight() - this.top
				- this.bottom);
		return result;
	}

	/**
	 * Expands an area by the amount of space represented by this object.
	 * 
	 * @param area
	 *            the area to expand.
	 * @param result
	 *            an optional carrier for the result.
	 * 
	 * @return The result.
	 */
	public Rectangle2D expand(Rectangle2D area, Rectangle2D result) {
		if (result == null) {
			result = new Rectangle2D.Double();
		}
		result.setRect(area.getX() - this.left, area.getY() - this.top, area
				.getWidth()
				+ this.left + this.right, area.getHeight() + this.top
				+ this.bottom);
		return result;
	}

	/**
	 * Calculates the reserved area.
	 * 
	 * @param area
	 *            the area.
	 * @param edge
	 *            the edge.
	 * 
	 * @return The reserved area.
	 */
	public Rectangle2D reserved(Rectangle2D area, RectangleEdge edge) {
		Rectangle2D result = null;
		if (edge == RectangleEdge.TOP) {
			result = new Rectangle2D.Double(area.getX(), area.getY(), area
					.getWidth(), this.top);
		} else if (edge == RectangleEdge.BOTTOM) {
			result = new Rectangle2D.Double(area.getX(), area.getMaxY()
					- this.top, area.getWidth(), this.bottom);
		} else if (edge == RectangleEdge.LEFT) {
			result = new Rectangle2D.Double(area.getX(), area.getY(),
					this.left, area.getHeight());
		} else if (edge == RectangleEdge.RIGHT) {
			result = new Rectangle2D.Double(area.getMaxX() - this.right, area
					.getY(), this.right, area.getHeight());
		}
		return result;
	}

	/**
	 * Returns a clone of the object.
	 * 
	 * @return A clone.
	 * 
	 * @throws CloneNotSupportedException
	 *             This class won't throw this exception, but subclasses (if
	 *             any) might.
	 */
	public Object clone() throws CloneNotSupportedException {
		return super.clone();
	}

	/**
	 * Tests this object for equality with another object.
	 * 
	 * @param obj
	 *            the object to compare against.
	 * 
	 * @return <code>true</code> or <code>false</code>.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof AxisSpace)) {
			return false;
		}
		AxisSpace that = (AxisSpace) obj;
		if (this.top != that.top) {
			return false;
		}
		if (this.bottom != that.bottom) {
			return false;
		}
		if (this.left != that.left) {
			return false;
		}
		if (this.right != that.right) {
			return false;
		}
		return true;
	}

	/**
	 * Returns a hash code for this object.
	 * 
	 * @return A hash code.
	 */
	public int hashCode() {
		int result = 23;
		long l = Double.doubleToLongBits(this.top);
		result = 37 * result + (int) (l ^ (l >>> 32));
		l = Double.doubleToLongBits(this.bottom);
		result = 37 * result + (int) (l ^ (l >>> 32));
		l = Double.doubleToLongBits(this.left);
		result = 37 * result + (int) (l ^ (l >>> 32));
		l = Double.doubleToLongBits(this.right);
		result = 37 * result + (int) (l ^ (l >>> 32));
		return result;
	}

	/**
	 * Returns a string representing the object (for debugging purposes).
	 * 
	 * @return A string.
	 */
	public String toString() {
		return super.toString() + "[left=" + this.left + ",right=" + this.right
				+ ",top=" + this.top + ",bottom=" + this.bottom + "]";
	}

}
